The objective of this project is to examine the relationships between the mass spectrum or other molecular features and pharmacologic activity of a drug molecule. The mass spectra of many groups of antineoplastic agents will be classified according to their relative potency in this L1210 screen. Correlations will be sought between the mass spectrum and biological activity with the aim of selecting those molecular features most prominantly associated with oncolytic effects. Although some members of a class of such agents are already in the clinic, we may discover that some of the other drugs may have properties suggesting they should be tested for possible greater clinical activity than those already in the clinic.